Field of the Invention (Technical field)
Biological and/or chemical fouling of heat exchangers in utility service water systems causing reduced heat transfer capability adversely affects operation and maintenance costs, and can force a power derating or even a plant shut down. In addition, service water heat exchanger performance is a safety issue for nuclear power plants, and the issue was highlighted by NRC in Generic Letter 89-13. Heat transfer losses due to fouling are difficult to measure and, usually, quantitative assessment of the impact of fouling is impossible. Plant operators typically measure inlet and outlet water temperatures and flow rates and then perform complex calculations for heat exchanger fouling resistance instrumentation.